Typewriting machine



May 29, 3923.

P. H. BURDICK TYPEWRITING MACHINE Filed Nov. 6, 1920 2 Sheets-Sheet l HUEHZ GI I Paul H Burdmk 5:

May 29; 1923.

P. H. BURDHCK TYPEWRITING MACHINE 2 Sheets-Sheet a Paul Hfiurdmk Filed Nov. 6, 1920 Patents Wiley 29, W3,

entree crass rat-can rarest; nice.

PAUL H. BURDICK, 01F GENEVA, ILLINOIS.

TYPEWBITING MACHINE.

Application filed November e, 1920. semi no. ceases.-

To all whom it may concern Be it known that I, PAUL H. BURDICK, a citizen of the United States of America, and a resident of Geneva, county of Kane,and State of Illinois, have invented certain new and useful Improvements in Typewriting Machines, of which the following is a specification.

My invention relates in general to typewriting machines, and the machine disclosed herein may be considered to be an improvement on the typewriting machine described in my prior application, Serial No. 407,928, filed Sept. 3rd, 1920. The object of the present invention is to incorporate certain new features and operating principles in a ma-. chine of the general character mentioned, whereby the speed of operation may be greatly increased.

In my prior application above referred to I have described a typewriting machine, or rathera controlling mechanism for a type writer, in which duplicate key sets are provided, one set for each hand of the operator,

and the number of keys in each set being far less than the number of letters or other characters to be written. The keys in each set are depressed either separately or in combination with each other, and the type bars are separately actuated by relay controlled magnets responsive to the actuation of the various individual keys and combinations of keys. Since two complete key sets are provided the operator can always use he'r two hands alternately, and the ma chine can therefore be operated much more rapidly and with greatiegr facility than the ordinary typewriter. y the present invention, however the speed of operation is still further increased, even over my former machine. 'In accordance with these improvements, I not only provide duplicate key sets, but these duplicate key sets are again duplicated. That is, two complete key sets are provided for each hand, and corresponding keys in each double set are posltloned adjacent each other so that' the operator can.

.depress key combinations corresponding to two characters simultaneously. Cooperating with the relays which control the opcrating magnets is a relay timing device,

which functions, when all the keys in two combinations are fully depressed, to'cause the character corresponding to the first combination to be-written, after which the said tion to be written.

- operation is repeate timing device, automatically and independently of the operator, then causesthe character correspondingrto the second combinahis operation, as stated,

is controlled by a single movement of the hand of the operator in which two combinations of keys are de ressed at once, and the d by using both hands al ternately. Since two characters are written in quick succession at each operation, the speed is greatly increased, and would in fact be exactly doubled were it not for the sli ht diiiiculty experienced in depressing two Eey combinations at once. This difiiculty, however, is more' apparent than real and 15 to a great extent overcome by practice. thermore, the single key combinations are asslgned to the characters'most frequently used, and the majority o'f the characters in ordinary matter therefore will be written by such easy combinations (most of themconsisting of only a single key) that two combinations can be actuated practically as easily as one. In addition to the principal features pointed out above there are other features, all of which will be fully described, hereinafter with reference to the accompanying drawings, in which I have shown suflicient details of the apparatus involved to enable the invention to be understood.

Referring to the drawings, Fig. 1 is atop view of "a standard typewriting machine mounted on the new control unit, the view showing clearly the arrangement of the duplicate key sets.

Fig. 2 is a side view of the apparatus shown in Fig. 1, and shows the general shape and construction of the control unit. A portion of the side of the unit is cut away at the rear in order to show the location and arrangement of the operating magnets.

Fig. 3 is an enlarged 'view of the key shelf, partly in section, and shows the construction of the keys and the method oi mounting the contact springs controlled thereby.

Fig. 4 is a circuit diagram showin how the operating magnets are controlled ythe he s through the mediumof relays.

nasmuch as the typewriting machine itself is old and well known, no detailed ex planation of the operation thereof will he given and no attempt has been made to show all the mechanical details in the drawings.

- tute duplicate sets a so, and these keys are I 12 are not included in the group of keys The line spacer, marginal stops, and all the other usual attachments except the word space bar and the shift are manually operated independent of the control unit. The explanation will, therefore, be confined to the control unit and its operation in actuating the operating magnets, whereby the machine iscaused to write.

Referring first to Figs. 1 and 2, all the apparatus with the exception of the operating magnet armatures is contained in a single unitary structure which comprises a box or casing 10, made of wood or other suitable material, and adapted to form a base for the typewriter with which the apparatus is to be used. At the rear and underneath the typewriter the hollow base or casing contains the operating magnets and the controlling relays, while the forward portion forms an extension or shelf which afiords a protection to-the keys. Suitablelegs or'supports for the base are provided as indicated.

The keys are 24 in number; Keys- 1 to 5, inclusive, and '1 to 5', inclusive,.are controlled by the right hand of theoperator; while keys 6 to 10, inclusive, and 6 to 10', inclusive, are controlled by the left hand. Considering the right hand keys 1 to .5, inclusive, these keys constitute a complete set through the medium of which all the required characters may be written. Key 1 is depressed b the thumb and the other four keys by t e four fingers. Keys 1' to 5, inclusive, constitute a duplicate set which is exactly like the first set, and it will be observed that the keys in the two sets are. so positioned that corresponding keys in both sets can be depressedsimultaneously. The keys operated b the left hand constiin fact just like those controlled by the right hand. Keys 13 and 13'- are the word 's ace keys and are common to both hands,

eys 11 and 12 are common keys also and control the shift and shift release; respectively.

Although the general arrangement ofthe keys is shown clearly in Fig. 1, the construction of the keys and the contact springs controlled thereby can best be explained by referring to Fig. 3, in which the last key on the right, the key 5, is exposed to view. The top portion, or key proper, is securely attached to an L shaped bar 30 which extends back through a slot 34 in the trans verse member 35 and is ivoted at its extreme end on the rod 36. ash of the other keys, with the exception of keys 11 and 12, similar to key 5, and the bars 31, 32, etc., extend back through their own individual slots in member 35 and are pivoted ,on rod 36 also- The rod 36 is supported at both ends and at several points throughout its length by brackets (not shown) at- ,tached to the base. Spacing washers are strung on the rod alternately with the key bars to maintain the-latter in their'proper positions Each key bar is provided with a coil spring, such as the spring 37 associated with bar 30, for restoring it to normal position. The extent of movement of the keys springs are indicated by reference characters 40, 41, and 42, and are attached'to the bar 30 by means of machine screws and insulating washers as shown. The two stationary springs 43 and 44 are similarly mounted on the fiat steel strip or bar 45, which extends the entire width of the base and has both ends bent down to formlegs which are suitably. attached to the sides of the casing. This steel strip supports all the stationary springs associated with the other keys, as well as the ones which can be seen in the drawing. All the spring combinations are adjusted the same. In the case of the spring combination shown, springs 42 and 4.4 are normally in engagement. When key 5 is depressed these springs are separated as soon as the key leaves its normal position, and all contacts are open until just before the key is, fully depressed, when springs 40 and 41 engage springs 43 and 44, respectively. As mentioned hereinbefore, keys 13 and 13 have slightly different spring combinations, each consisting only of two springs corresponding in position and adjustment to springs 40 and 43 of key 5'.

The shift and shift release keys 11 and just described, but are pivoted in any suitable manner on the transverse member 35. These keys each control a single pair of contacts and are in reality nothing more than push buttons. Any suitable method of attaching these keys can be used, and

they can be omitted altogether if desired,

will not therefore be necessary-to include a detailed description of themherein. It should be stated, however, that the present circuit arrangements provide for only thirty magnets, rather than forty five. Twenty six of the magnets correspond to the twenty-sixletters of the alphabet, while the remaining four magnets are assigned to various punctuation marks, as will be explainedpresently.

The relays are not shown except in the circuit diagram, Fig. 4:, but are ordinary relays such as are in common use in telephone systems throughout the country. They may be mounted on suitable relay strips in the base just forward of theoperating magnets, or they may be mounted in a separate box which is thenconnected with the control unit by a flexible cable.

As a source of current supply a 12 volt storage battery may be used, such as are used in automobile starting and lighting systems. This is the preferred way of supplying current for asingle machine, but if a large number of machines are'to be installed at a single point, as for instance, in some large oiiice building, a single central battery can be used, and it will then be economical to employ a higher voltage.

Referring now to the circuit diagram, Fig. 4, the right hand keys 1 to 5, inclusive, and 1 to 5, inclusive, are shown diagrammatically in the upper right hand corner, while the corresponding key sets for" the left hand, indicated by reference characters 6 to 10, inclusive, and 6 to 10', inclusive, are similarly shown in the upper left hand corner. The word s ace keys 13 and 13' and the shift and shift release keys 11 and 12 are shown in the center. At

, the lower left corner of the sheet are shown the operating magnets. These magnets are thirty in number, exclusive of certain special magnets to be mentioned, and are divided into two groups. Relays to 54, inclusive, which may be controlled by any one of the four sets of finger keys, control the selection of magnets within groups; while relay 63, which may be controlled by any one of the four thumb, keys, controls the group selection. Relays 57 and 58 are eommon to the left and right hand key sets,

respectively, and their function is to Relays 55, 56, 60, 61,

revent interference. p and 62 control the striking of the different characters by the operating magnets responsive to the operation of the selecting relays, and certain of these relays also control the striking of two characters in quick succession responsive to the simultaneous actuation of two key combinations. Relay 59 is associated with the word space keys 13 and-13' The magnet 64' is the word space'magnet and operates the word space bar. Magnets 65 and 66 operate the shift and shift release bars, respectively.

It should be understood that the permutational relays 50rto 54, inclusive, are normally under the control of only a single key set for each hand, the duplicate or prime numbered sets being inoperative to efl'ect energization of the relays without the operation of keys in the other sets. For

keys in any set. depressed singly and in.

combination, is the same as described in my prior application and hence wlll be readily understood. A new code has been devised,

however, which is shown in the table appended below:

Letter or character. 'l o w rite E e Key combination. dergcss key 2 piwoa kcvs 1 and 2 u 2: u

n n i u u Unassigned To operate word space bar key 13 H H ft (1 l u u 41 release it The above table includes twenty nine combinations, leaving one unassigned which may be usedfor any additional punctuation marks or characters desired. Although the key numerals included in the table all refer to the first of the right hand key sets, it will be understood that the table applies to each of the other three key sets in the same way. It will be noticed also that there are no combinations which correspond to the ten figures or digits. The figures occur infrequently, but when they do, they can be written by reaching forward to the typewriter keyboa 'd' and striking the usual keys by hand. I

The operation of writing certain charac- -ters will now be described with a view to left hand keys.

contact oft-key 5, resting contact of armature 83 and the said armature, and the windings of relays 53 and 54 in parallel to battery. Upon the closure of the above-circuit, relays 53 and 54- are energized in series with relay 58, and the latter relay, upon energizing, disconnects ground G from the winding of relay 57 and therefore from conductor 100 which Supplies ground to all of the This is done in order to prevent the possibility of interference by the. accidental depression of one or more of the left hand keys before the right hand key or keys are released. The energization of relay 54 is without essential effect at this time, but relay 53, upon energizing, closes the following circuit: ground at G", armature 85 and its resting contact, armature 86 and its resting contact, armature 87 and its resting contact, armature 88 and its work- 7 ing contact, conductor 89, winding of magnet 67, resting contact of armature 90 and the said armature, conductor 91, armature 92 and its resting contact, right hand winding of the double wound relay 61, and the resting contact of armature 93 and the said armature to battery. The right hand winding of relay 61 is of very low resistance and accordingly when the above circuit is closed the magnet 67 is operatively energized. This magnet is located beneath the type bar corresponding to the letter A and, upon energizing, it actuates the type bar to write such letter, the same as if the key were struck manually bythe operator. Relay 61 is madeslightly slow acting by means of a ring or slug of copper onv the core and does not pull up its armature at once when the circuit is closed. An instant later, however, and immediately after the required letter has been written, armature 93 is attracted and the left hand winding of relay 61 is connected in series with the right hand winding in the circuit of the operating magnet'67. The left hand winding is of extremely high resistance and its insertion in the circuit,therefore, causes magnet 67 to immediately retract its armature, relay 61 remaining energized. with current flowing through its two windings in series. When the circuit is broken by the restoration of key 5 to normal all the relays return to their normal positions. It is noted that relay 61 should be adjusted so that the attraction of its arma-.

ture is delayed just long enough to permit any magnet connected in series with it to be fully energized.

The letter A. is written by one of the magnets in the upper group, and the writing of another letter will now be explained in order to show how the magnets'ot the lower group are actuated. The .upper group of magnets is "normally connectcdito l'iatteryand any magnet in this group may be operated by using the fingerkeys alone, but to operate a magnet in the lower group the thumb key 1 must be actuated in order to'shift the battery connections. Suppose now that the letter N is to be written. According to the table the combination for this letter requires keys 1 and 2 to be depressed. These keys are both depressed simultaneously and when both keys are fully actuated so that theloop circuit including their upper contacts is closed a circuit is completed for relay 63, which extends from the'grounded conductor 82 by way of the lower make contact of key 1, resting contact of armature 94 and the said armature, conductor 95, and the winding of relay 63 to battery. Upon energizing, relay 63 disconnects conductor 91 from all the magnets in the upper group and connects it instead to the magnets of the lower group. At the same time that the circuit of relay 63 is closed a circuit is completed for relay which extends from the grounded conductor 83 by; way of the lower make contact of key 2, resting contact of armature 96 and the said armature, and the winding of relay 5O to battery. Upon energizing, relay 50 closes the following circuit for operating magnet 68: ground at G armature 85 and its working contact, armature 97 and its resting contact, armature 98 and its resting contact, armature 99 and its resting contact, conductor 101, winding of magnet 68, working contact of armature 102 and the said armature, conductor 91, armature 92 and its resting contact, right hand winding of relay 61, and the resting contact of armature 93 and the said armature to battery. When the above circuit is closed magnet 68, which is positioned below the type bar corresponding to the letter N, is operated momentarily to strike the required letter. The magnet is caused to deenergize an instant later by the operation of relay 61 as in the previous case. When the keys 1 and 2 are restored all the circuits are broken and the relays nanred are deenergized. it is noted that in both of the cases just described relay 61 closes a circuit through the left hand winding of relay 60, and this re lay is of course energized also, but its opera tion when only a single set of keys is in use need not be considered.

In View of the foregoing the process of actuating the remaining operating magnets to write the other letters and characters Will beunderstood without difficulty. It may be explained, however, that the battery connections of all the magnetsare controlled by relay 63 in the same manner that the connections of the first six magnets at the left are controlled. That is, this relay is in practice provided with sufiicient contact springs to control thebattery connections of all the magnets individually, but since the connections are all the same it is considered unnecessary to show thecomplete circuits of more than six. If desired, the fifteen sets of contact springs which will be required ma be divided among two or more relays which are connected in parallel or in series.

It is understood, that the letters A and N and all the other lettersand characters can be written with the left hand just as well as with the right, and in practice, assuming series relays 57 and 58, each of which interrupts the ground connection to the keys associated with the other. If any right hand key is depressed, relay 58 is energized and disconnects ground from the left hand keys; while it any left hand key is depressed relay 57 is energized and disconnects ground from the right hand keys. This circuit arrangement prevents confusion in casethe operator should happen to depress one or more keys with one hand before the key or keys depressed by the other hand are released.

The foregoing explanation has been considered necessary in order to explain how the magnets are selectively controlled by the depression of the keys in some key set singly or in combination, and although the machine may be operated in the manner just explained if desired, this is not the mode of operation contemplated by this invention, as will doubtless be evident when it is recollected that no mention has so far been made of the keysin the right and left duplicate key sets. In order to explain the use of these keys it will be assumed that the word THE is to be written. Consulting the table, it will be seen that the letter is-written by depressing key 3, while the letter H is written by depressing keys 2 and 3 simultaneously. Using her right hand, the o erator may therefore depressrkey 3 in t e first key set with the second finger of her right hand, while at the same time keys 2' and 3' in the second ke set are depressed with the first and secon fingers. All three keys are depressed at once, and the simultaneous actuation of keys 3 and 3' by the same finger is accomplished by placing the end of the finger over the crack between the two keys. As shown in the drawings, corresponding keys in the two sets are close together and with the same finger, therefore, the operator can readil operate corresponding keys in both sets. en all the keys are depressed, and the loop circuit including the upper contacts is closed, a. circuit is com-.

pleted for relays 58 and 51 in series, the circuit including the conductor 82,- the lower make contact of key 3, and the normally closed contact atarmature 103. Uponenergizing, relay 51 closes a circuit for magnet 105 which may be traced from ground G by way of armature 85 and its resting contact,

armature 86 and its working contact, normally closed contacts controlledby relays 52 and 53, conductor 10%, winding of maet 105, normally closed contacts controllef by relay 63, armature 92 and its resting contact, left hand winding of relay' 61, and the resting contact of armature 93 and the said armature to battery. Upon the closure of the above circuit, magnet 105 is operated momentarily to strike the letter T. Relay 61 is energized in series with the operating magnet 105, and upon attracting its. armature 93, connects its left hand winding in the circuit to cause the said magnet to retract its armature. At the same time relay 61 closes a circuit for the left hand winding of relay 60 which, upon energizing, establishes a locking circuit for itself at its armature 106, and at its armature 107 closes a circuit through relays 55 and 56 in parallel. It is noted that conductor 108, which is included in both of the above circuits, is grounded at the working contact of armature 109 of relay 58. As a result of the energization of re ay 55, relays 50 to 54:, inclusive, and relay 63 are disconnected from the keys in the first key set and are connected instead to the ke s in the second or duplicate-key set. At t e same time, by the energization of relay 56, conductor 91 isdisconnected from role. 61 and is connected instead to relay 62. eys 2' and 3' in the duplicate key set being now in depressed position, circuits are completed for relays 50 and 51, and these relays are energized to complete a circuit for magnet 111 as follows: ground at G armature and its working contact, armature 97 and its working contact, normally closed contacts controlled by relays 52 and 53, conductor 110, winding of magnet 111, normally closed contact springs controlled b relay 63, conductor 91, armature 92 and its working contact, right hand winding of relay 62, and the resting contact of armature 112 and the said armature to battery. 13y the operation of magnet 111, which is located beneath the type bar associated with the letter H, this letter is written in the usual manner. Relay 62 is exactly like relay 61 and o crates to include its. left hand winding in t e circuit in order to deenergize the operating magnet. It is understood that the various relay operations described takesfplace' very quickly, and the letters T and lay 60 and at the same time breaks the circuit extending through relays 55 and 56.

Relay 61 has already been deenergized by the transfer of conductor 91 to relay 62.

The operator will now de ress keys 7 and 13' with the left hand, key I being operated by the first finger and key 13 with the thumb. As a result of the actuation of key 7 a circuit is com leted for relay 50 in series with relay 5.7. pon' energizing, relay 5O completes a circuit for magnet 114 which may be briefly traced from ground Gr by way of armature 85 and its working contact, normally closed contacts controlled by relays 51, 52,-and 53, conductor 101, winding of'magnet 11 i, resting contact of armature 102 and the said armature, conductor 91, armature 92 and its resting contact, and thru the-right hand winding of relay 61 to battery. Ma et 114 is accordingly operated momentari yto-strike the letter, E. Relay 61 is energized as usual and closes a circuit for relay 60. Upon energizing,- relay 60 closes a locking circuit for itself at its arma ture 106, and at its armature 107 completes a circuit for relays 55 and 56 in parallel. The energization of the former relay is without particular eflect at this time,but the latter relay, upon attracting its armature 116, disconnects the conductor 115 from key 13 and connects it instead to key 13", while at its armature 92, it transfers the conductor 91 from relay 61 into connection with relay 62. The word space key 13 being .now in depressed position, a circuit is completed for magnet 64, which extends from ground Gr through the winding of low resistance relay 59, make contact of of armature 116 and the said armature, conductor 115, winding of magnet 64;, conductor 91, armature 92 and its working contact, and the right hand winding of relay 62 to battery. Magnet 64 is the magnet which opcrates the word space bar and is operated momentarily at this time in order to advance.

the typewriter carriage one space. As soon as the spacing has been accomplished, keys 7 and 13 are released, and the relays which have been energized fall back as before.

These operations may be continued as long as desired, two letter combinations being depressed simultaneously, first with one hand and then with the other, and the letters corresponding to the depressed combinationsv will be written in rapid succession. It will be observed that when only one letter is required to complete a word, as in the case described, the spate key 13 is operated simultaneously with the key or keys corresponding' to such final letter. 1 However, it will occur an equal number .of times that the last two letters of a word are written with the same hand, and: whenever this happens a space ke will be operated simultaneously with the ey or keys which correspond to the first letter ofthe next word. For instance, suppose that a word containing four letey 13', working contactters iswritten. The first two letters may be written by a single. operation of the r ght hand and the next two by a single operation of the left hand. Since this just completes the word, the first letter of the next word will, in reality, and according to the operv ating principles herein provided, be a space, and the operator will: accordingly depress with her right hand the space key, 13'and: the other keys which correspond to the initial letter in the word to be written next, being carefulto use, however, the he s such as 1, 2', etc., of the second key set. ey13 is "nor.-

'mally in readiness to actuate the word space magnet 6 1, and this magnet is. accordingly operated at once to. advance the typewriter carriage one space, after which the relay circults are shifted by the energization of.re-

Relay 59, which is energized whenever either ofthe space keys is depressed, has the function of grounding conductor 108, but. this relay is unnecessary when the space .95 keys are actuated simultaneously with one or more keys in the regular key sets, as in such cases. either relay 57 or relay 58 will also be energized. 'But it may he a double space is required, in w rch case en that keysl3 and 13 will both be'depressedsimultaneousl", key 13 then operates magnet-6e 1 for the 'rst space, and relay 59 isenergized to supply ground to conductor 108 while key 13 is operating the said magnet v for the second space. h I

In the foregoing explanation it has been assumed for convenience that capitalized letters-are to be written,which-of course requires the key tobe operated. ,7 Without using the shift key the corresponding small type letters will 'beiwritten i'nsteadxof the capitals. The shiftke'y and the shitt re lease key may be operated manually if de sired by reaching up to the typewriter keyboard, or bars corresponding to these keys may be operated from the control unit by depressing keys 11 and 12, whichcontrol the circuits of magnets .65 and 66.

Having described my invention, what .I consider to be new and desire to have protected by Letters Patent will be pointed out in the aplpended claims.

What claim is:

1. In a typewriting machine, a )lurality of letter keys and a word space key, and means responsive to the simultaneous actu-' ation of a letter key and said space key for advancing the carriage of said machine one space, for then writing the letter corresponding to the actuated letter key, and for then advancing the carriage another space.

2. In a typewriting machine, a plurality of letter keys and two word space. keys, means responsive to the simultaneous actuation of a letter key and one of said space keys for writing the proper letter-and for advancing the carriage of the machine two spaces, and means for causing the said letter to be written either before the carriage is advanced or after the first space and before the second space, depending on which of said space keys is operated.

3. In a typewriting machine, four sets of keys, writing devices common to said key sets, means causing two of said writing devices to respond successively when keys in all four sets are actuated simultaneously, andmeans causing two more of said writing devices to respond successively when the keys in two of said key sets are restored.

4. In a typewriting machine, a plurality of writing devices, controlling mechanism comprising keys operable singly and in permutations for actuating any two ofsaid devices successively and in any desired order by a single movement of the hand, and means supporting said keys in close proximity to each other to enable any desired plurality of them to be reached and operatedwith one hand as set forth.

5. In a typewriting machine, a plurality of writing devices, and controlling mechanism comprising keys operable singly and in permutations for actuating any four of said devices successively and in any desired order by a single movement of each hand.

6. Ina typewriting machine, four duplicate key sets, two for each hand, writing devices common to all of said My sets, and consecution controlling means for causing the writing of a plurality of characters in succession responsive to the simultaneous actuation of keys in both right hand sets followed by. the simultaneous actuation of keys in both left hand sets.

7. In a typewriting'machine, a pluralit of writing devices, a set of keys for contro ling said devices, and a duplicate set of ke 's for controlling said devices, the keys of the duplicate set being located adjacent the keys of the first set so that corresponding keys of both sets can be actuated simultaneously with one hand.

8. In a typewriting machine, a set'of keys,

a duplicate set havlng its individual keys located adjacentand close to the corresponding keys of the first set, so that the operator can actuate keys in bothsets simultaneously with one hand, and aplurality of writing devices common to said key sets.

9, Ina typewriting machine, a set of keys, aduplicate set having its individual keys located adjacent and close to the corresponding keys of the first set, so that the operator can actuate keys in both sets simultaneously with one hand, a plurality of writing devices common to said key sets, and means for causing said writing devices to respond successively to simultaneously actuated keys in the said key sets.

10. Ina typewriting machine, a plurality of operating magnets,a lesser plurality of permutational relays for controlling said magnets separately, at set of keys normally connected to said relays, a set of normally disconnected keys, and a transfer relay for disconnecting the normally connected keys and for connecting the normally disconnected keys.

11. In a typewritingmachine, a plurality of operating magnets, a lesser plurality of permutational relays for controlling said magnets separately, a set of keys normally connected to said relays, a set of normally disconnected keys, and means timed with respect to the operation of any of said magnets for transferring the connections to said relays from the first set of keys to the said second set.

12. In a typewriting machine, a plurality.

of operating magnets, a lesser plurality of permutational relays for controlling said magnets separately, a set of keys normally connected to said relays, a set of normally disconnected keys, a timing device for limiting the operating time of any magnet operated responsive to. a key in the said first set, and transferring means controlled by said timing device for shifting the connections of said relays from the said first set of keys to the said second set.

13-. In a typewriting machine, a plurality of operating magnets, a timing device for limiting the o crating time of said magnets, said device being normally connected in circuit with said magnets, a second timing device, and switching means operated automatically when any magnet is energized for disconnecting all said magnets from the said first timing device and for connecting them in circuit with said second timing device.

14. In a typewriting machine, a spacing magnet, a space key normally connected to said magnet, a second space key, and means responsive to the operation of said first key for transferring the connection of said magnet from said first space key to said second space key.

15; In a typewriting machine, a spacing magnet, a space key normally connected to said magnet, a second space key, letter keys and printing magnets responsive thereto,

and means responsive to the actuation of any letter key for shifting the connection of said spacing magnet from said first space key to said second space key.

16. In a typewriting machine, rightand left hand sets of finger keys, right and left hand thumb keys between the two sets of ,finger keys, a'space key located between and close to both thumb keys, whereby said space key may be depressed simultaneously with either thumb key, writing devices arranged in groups controlled by said finger keys, and group selecting mechanism controlled by said thumb keys.

17. In a typewriting machine, a plurality of keys, all adapted for operation with one clusively for operation with the other hand.

18. In a typewriting machine, a plurality of keys, all adapted for operation with. one hand, a plurality of writing devices responsive to said keys when actuated singly,

other writing devices responsive to said keys when actuated in combination, means for causing the corresponding writing devices to respond successively when a plurality of sin gle keys or combinations of keys are actu-- ated simultaneously, and other keys operated exclusively with the other hand either singly or in combination to control said writing devices.

19. In a typewriting machine, two' complete sets of keys both for operation exclusivelywith one hand, other keys operated exclusively with'the other hand, and means responsive to the simultaneous actuation of neeaeas keys in both of said first sets for Writing a plurality of characters successively.

20. In a typewriting machine, a set of keys for writing all the letters of the alphabet, all otsaidkeys being adapted for operation with one hand, a duplicate key set adapted for operation by the same hand, writing means responsive to the simultaneous actuation of keys in both sets for writing the corresponding letters successively, and other keys adapted exclusively for operation by the other. hand for also controlling said writing means.

21. In a typewriting machine,a plurality of letter keys, a word space key, writing mechanism, spacing mechanism, and controlling mechanism intervening hetween the said keys and mechanisms responsive to the simultaneous actuation of a letter key and said space key for writing the proper letter and for advancing the carriage of said machine both before and after the letter is Written.

22. In a typewriting machine, two keys, a writing device common to said keys, and controlling mechanism rendering said writing device responsive only to one of said keys when said keys are operated separately,

and rendering said writing device responsive to both keys one after the other whenever the second key is depressed prior to the release of the first key.

Signed at Geneva, county of Kane, and State of Illinois, this 1st day of November,

PAUL H. BURDICK, 

